1. Field of the Invention
The present invention relates to an optical switching device and optical transmission system used in wavelength division multiplexing (WDM) optical communications and the like.
2. Related Background Art
An example of optical switching device used in WDM optical communication systems is a wavelength-selective switch disclosed in Document 1, i.e., OFC 2002 Postdeadline Papers, FB7-1, “Wavelength-selective 1×4 switch for 128 WDM channels at 50 GHz spacing”. This wavelength-selective switch comprises a plurality of I/O ports, each constituted by an optical fiber and a lens, a diffraction grating, and a MEMS mirror which are combined together, thereby making it possible to attain a smaller size and a lower cost.